The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 08, 1992
Filed:
Aug. 28, 1990
Hitachi, Ltd., Tokyo, JP;
Hitachi Video Engineering, Inc., Tokyo, JP;
Abstract
A circuit pattern to be inspected is imaged so that an image signal representing the circuit pattern to be inspected is produced. The image signal of the circuit pattern is compared with a reference circuit pattern image signal, wherein a part of the image signal discerned to be different from the latter is detected as a candidate defect, at a rate synchronized with the rate of imaging. A local image signal corresponding to each local image covering a region including every one of detected candidate defects is extracted and stored in a memory device. Thereafter, on the basis of the local image signal read out from the memory device, whether or not the candidate defect concerned is fatally harmful with regard to electrical conductivity is examined at a rate asynchronous with the imaging rate.